Flame boring apparatus



April 17, 1956 R. w. MURRAY 2,7

FLAME BORING APPARATUS Filed Oct. 3, 1952 2 Sheets-Sheet INVENTOR.ESOBERT W) MURRAY ATTORNEYS WHITEHEAD 8| VOGL PER a Flg I United StatesPatent "ice FLANIE BORING APPARATUS Robert W. Murray, Denver, Colo.

Application October 3,1952, Serial No. 312,950

9 Claims. (Cl. 219-14) This invention relates to flame boring anddrilling apparatus of that class which is primarily adapted for drillinginto rock, having as an object the provision of a new and improved flameboring apparatus which combines a gas flame with an electric arc.

Other objects of this invention are to provide an improved flame boringapparatus which combines a gas flame with an electric arc and which: (a)is adapted to produce such intense heat that the operation of the flameboring into a rock may proceed at a rapid rate; (b) ionizes theintensely hot gases to facilitate chemical reactions with certainconstituents of the rock and thereby accelerates the boring operations;(0) provides means for supplying water or other liquid to the heatingarea to thereby cool the drill stem, to thereby form a steam blast toremove particles from the bore, to thereby react chemically with rockconstituents and to thereby suddenly cool and disintegrate andscintillate heated and molten substances as minute particles; (d)includes an improved drill stem construction adapted for extension byinterconnection with additional lengths of stem during a drillingoperation; (2) includes improved arcing means comprising electrodesadapted to move together as the arc commences; and (f) is a simplyconstructed, easily operable apparatus adapted to rapidly andefliciently bore a hole into any type of rock.

With the foregoing and other objects in view, all of which more fullyhereinafter appear, my invention comprises certain new and novelconstructions, combinations and arrangements of parts and elements ashereinafter described and defined in the appended claims andillustrated, in preferred embodiment, in the accompanying drawing, inwhich:

Figure l is a diagrammatic elevation view of my improved flame boringapparatus carried upon a derrick and positioned for drilling a verticalhole into a body of rock.

Figure 2 is a transverse section through the drill stem as viewed fromthe indicated line 2-2 at Fig. 1, but on anenlarged scale.

Figure 3 is a sectional elevation of the drill stem as viewed from theindicated line 3-3 at Fig. 1, but on an enlarged scale and with portionsbroken away to conserve space.

Figure 4 is a fragmentary section of the head carrying the drill stem,as viewed from the indicated line 4-4 at Fig. 3.

Figure 5 is a diagrammatic elevation similar to Fig. l, but showing analternate construction wherein the boring operation is in a confinedpressurized space.

Figure 6 is a sectional detail of the leading end of an alternateconstruction of the drill stem on an enlarged scale.

Figure 7 Ba transverse section as viewed from the indicated line 7-7 atFig. 6.

Figure 8 is a section similar to Fig. 7, but showing an alternateconstruction of the conductor elements for creating an electric arecovering the leading face of the drill stem.

2,742,555 Patented Apr. 17-, 1956 One conventional apparatus for flameboring into rock is simply an iron pipe through which a combustiblemixture of gas is passed to the leading end of the pipe. The gas, whichis primarily oxygen, burns into the rock and also burns away the end ofthe iron pipe to produce an intensely hot flame, by the reaction of theoxygen with the iron. The heat is suflicient to melt the rock and topermit it to flow from the hole as the burning operation proceeds. Theconventional types of flame boring apparatus have definite limitations.For example, this and other conventional types are expensive to operatebecause of the large quantities of gases which are used and because theiron pipe burns up rapidly or the intensity of the heat must beundesirably restricted.

It has long been recognized that if it were not for such limitations, aflame boring apparatus for boring holes into rock would be very.desirable because of the speed at which such an operation can proceed.With the foregoing in view, the present invention was conceived anddeveloped, and comprises, in essence, an apparatus for flame boringwhich uses a drill stem 10 formed with a tubular core 11 having withinit a passageway 12 for oxygen and passageways 13 for a fuel gas. Thiscore is enclosed by a refractory type insulating sheath 14 into which isembedded electrical conduits 15 and a passageway 16 for water. Theoperation of my improved drill stem, by apparatus hereinafter described,includes flowing oxygen and fuel gas through passageways 12 and 13 tothe leading end of the stem 10, forming an electric arc across theleading ends of conduits 15 and flowing sufficient water through thepassageway 16 to provide a desired amount of cooling and steam for theejection of particles as the drilling operation proceeds.

With this arrangement of elements, the action of th are, combined withburning gases, creates an extremely high temperature which is sufiicientto melt and vaporize practically any known substance. Nevertheless, themovement of water through the passageway 16 keeps the leading end of thedrill stem suflieiently cool so that it is not burned away at such arapid rate that the boring operation becomes ineflicient because of thecost of replacing drill stems. As the water is ejected from the drillstem, it is vaporized into steam, and in combination with the gasesresulting from combustion, creates a blast which removes particles fromthe hole being drilled.

The amount of Water used during a boring operation and the manner inwhich it is used will depend upon the type of rock encountered. A rocksuch as limestone which will calcine by the action of heat can be boredat a relatively low temperature and the blast will remove the calcineddust from the shaft. A rock such as granite will require a more intenseheat suflicient to disintegrate spall and separate the crystallineparticles of felspar and quartz by difierential expansion, and it may beeven necessary to melt some of the substances constituting the rock.When boring a rock such as quartz, still more intense heat must be usedto melt the quartz and it is desirable that the water be intermittentlyforcibly ejected from the drill to atomize or break up and disintegratethe mass and scintillate the particles into a dust by sudden cooling.

The apparatus shown at Fig. 1 is mounted in a derrick 17, which may beof any conventional construction, hav ing a hoist 18 at its top operableto raise or lower a lead screw 19 at any selected rate by controls notshown herein. The lead screw 19 carries a connector head 20 to which thedrill stem 10 is attached in a manner herein described. The connectorhead is mounted within a wheeled carriage 21 which is confined withinvertical guides 22 of the derrick 17.

This derrick is mounted in position for drilling a hole S with the stemdepending from the head in line with the hole axis. This stein extendsthrough an orificed guide sleeve 23 which is mounted between the guides22 at the bottom of the derrick, and this sleeve includes a deflectorplate 24, which is adapted to deflect the exhaust gases and particlesejected from the hole S in a selected lateral direction during thedrilling operation.

The accessory equipment essential to the operation of the apparatusincludes a water supply tube 25 which may be hung from the derrick 17 asover a pulley 26. Conventional valve or regulation means, not hereinshown are interposed in this line 25 to regulate the flow of water tothe stem. Electrical power may be supplied through a conventionaltransformer 27 to a voltage regulator 28 having a lead 29 for connectionwith electrical conduits 15 Within the drill stem. The oxygen and fuelgas are supplied from tanks 36 and 31 respectively, which includesuitable pressure regulating and control valves as indicated at 32. Therespective lines 33 and 34 from the oxygen and fuel tanks, the lead 29and the water line 25 are all connected into the head 29 for connectionwith passageways and conduits within the drill stem 10.

The drill stem 10 is formed as a plurality of interconnected sections,such as indicated at Min, 1% and 10c at Fig. l, to permit it to beextended for drilling to any desired depth. These sections are joinedtogether in any conventional manner which will permit the electricalconduits 15 and passageways 12, 13 and 16 of one drill stem section tocontact and register with the corresponding conduits and passageways ofthe adjacent section to provide continuity of conduits and passagewaysthroughout the stem.

in the drawing the drill stem sections are shown as joined together byusing the electrical conduits 15 as a fastening means. This is possiblewhere the conduits are made of metal or a material having acomparatively high tensile strength. Both of the electrical conduits 15extend from the top of a section 10 to form tapered dowels 35 andcorresponding tapered sockets 36 are formed in the bottom of eachsection. The dowels 35 at the top of one section 10 are simply insertedinto the sockets 36 at the bottom of an adjacent upper section and theyare locked into position by screws 37 which are inserted into orifices38 in the wall of the upper section it? opposite the sockets 36 and intothreaded orifices 3? through the dowels 35. To provide a better seal atthe joint where two sections it) are interconnected and to avoid gasleakage, the core 11 of the upper section 10 extends below the bottom ofthe sheath 14 and into a socket 40 at the top of the lower section whichis formed 3 by terminating its core 11 below the top of the sheath 14.

The head 2t? is the focus of the apparatus, for it is the point ofinterconnection of the drill stem 10 with the hoist lead screw 19, thewater supply line 25, the gas lines 33 and 34 and the electrical lead29. This head is divided into two portions, the upper portion being arectangular block forming part of the carriage 21 and being attached tothe lead screw 19. The lower portion is a collar 41 formed of aninsulating type of material which includes a socket 42 at its undersideinto which the top of the drill stem 10 is inserted for connectionthereto. A short cylindrical core 43, concentric with the socket 42,extends through the collar 41 and into the socket 42, the extendedportion being adapted to fit into the socket 44 at the top of the drillstem 10 and against the end of the core 11. The top of the core 43 isnarrowed to a central stem 44 which is within a chamber 45' in the upperportion of the collar 41 and lower portion of the head 20. A passageway46 extends through the core 43 and stem 44 to register with the centralpassageway 12 of the drill stem and a passageway 47 in the 7 head 20.The oxygen line 33 is connected in the head 20 to the passageway 47whereby the fiow of oxygen from the line 33 is through passageway 47 andto pas- 4 sageway 12 of the stern. A passageway 48 extends through thehead 20 and to the chamber 45, and the fuel gas line 34 is connected inthe head 20 to this passageway 48. Passageways 49 extend from thechamber 45 through the core 43 to register with passageways 13 of thestem it). The flow of fuel gas from line 34 is thus through thepassageway 48 to the chamber 45, through passageways 49 and to thepassageways 13 of the drill stem 10.

The collar 41 has openings 50 which are adapted to receive theupstanding dowels 35 at the top of the drill stern and to receivefingers 51 which depend from the head 23 for contact with and engagementto the dowels 35. The engagement is secured by lock screws 52 which aremounted in orifices 53, in each side of the collar, and which extendthrough orifices 54 of fingers 51 and orifices 39 of the dowels 35. Inthis manner the head 2%, the collar 41 and the drill stem 10 areinterconnected.

Gas-tight seals are made between the surfaces of the head 20 and collar41 and between the collar and drill stem it by suitable ring gaskets 55and 56 respectively.

The fingers 51, connecting with the dowels 35, are electrical conduitswhich extend through the head 20 within an insulating sheath 57 andterminate at their upper end as threaded studs 58 to which theelectrical leads 2? are connected. The connection of each electricallead 29 is suitably enclosed within an insulating cap 59.

The water supply line 25 is connected to the head 20 in a passageway 60which extends through the head 26 and through the collar 41 to a pointof registration with the passageway 16.

The apparatus may be modified in several ways. The constructionillustrated at Fig. 5 shows the drilled hole S enclosed at its top by adiaphragm 61 which includes an orifice 62 through which the stem mayextend. The space within the hole is thereby enclosed for operation andburning under pressure. A tube 63 extends from the diaphragm 61 to atank 64 which has a restricted discharge orifice 65 in its top. The flowof gas from the hole S is thus through the tube 63 into the tank 64 andthence from the orifice 65. The orifice is sufficiently restricted tocreate an increased pressure within the shaft and within the tank, yetto permit a flow of gas of suflicient velocity that the particles whichare scavenged from the hole are moved by the flow of gas into the tank.With such an arrangement, a control of temperature is possible.

Figs. 5, 6 and 7 illustrate bi-metallic electrical conduits 15 formedwith an exterior layer of metal 66, the-layers on the respectiveconduits having different thermal coefiicients of expansion, whereby theheating of the conduits at the bottom of the drilled hole causes them tocoincidentally move toward each other to restrict the burning to theends of the electrodes, as clearly illustrated at Fig. 6.

Figure 8 shows an alternate construction of a drill stern having fourelectrical conduits 15" (although any suitable number may be used),positioned around the core 11. It is contemplated that severalelectrical currents can be passed through these conduits to create arcsbetween the various conduits 15" and form a composite are which coversthe leading face of the drill stem 10 and provides an intensely hotflame.

While I have illustrated and described many details of construction,alternatives and equivalents will occur to those skilled in the artwhich are within the scope and spirit of my invention; hence it is mydesire that my protection be not limited to the details hereinillustrated and described, but only by the proper scope of the appendedclaims.

I claim:

1. A gas-arc flame-boring apparatus including, in combination, a drillstem having passageways in the center of the stern and electricalconduits at opposite sides of the passageways longitudinally throughoutits length, a head carrying said stern, and adapted to move an endof thestem at a selected rate into a hole during a boring operation, means forsupplying a combustible mixture of gas to the head, passageways in thehead connecting the gas supplying means with said passageways in thestem leading to said stem end, means for supplying electrical power tothe head and means Within the head connecting said power supplying meanswith the conduits in the stem whereby to form an electric are at the endof the stem and to ignite and combine with gas emitted from saidpassageways between the electrical conduits.

2. The flame-boring apparatus defined in claim 1 including means forsupplying water to the head and through a passageway in the stem.

3. The flame-boring apparatus defined in claim 1 including a deflectorplate inclinedly carried upon the stem near the head whereby to deflectgas and detritus from blowback as the apparatus is drilling a hole.

4. A drill stem for flame-boring apparatus comprising a plurality ofsections, each having a core with longitudinal passageways therethroughand an insulating refractory sheath surrounding the core and electricalconduits embedded within the sheath, and means for interconnecting saidsections with the core-passageways and conduits of each sectionconnected with and forming continuations, respectively, of thecore-passageways and conduits of the adjacent section.

5. The stem defined in claim 4 wherein said connecting means comprisedowels at the tops of the sections and dowel receiving sockets at thebottoms of the sections.

6. The stem defined in claim 5 wherein said dowels are extensions of theelectrical conduits and said sockets are within the electrical conduits.

7. The stem defined in claim 6 wherein said core extends below thebottom edge of the sheath at the bottom of each section and terminatesbelow the top edge of the sheath at the top of each section.

8. A gas-arc flame boring apparatus, including, in combination, a drillstem having a passageway extending longitudinally therethrough, a pairof electrical conduits extending longitudinally along the stem, saidstem including a refractory type insulating material electricallyseparating said conduits along the stem, said conduits being spaciallyseparated to permit the formation of an are at one end of the stem and ahead at the other end of the stem having connection means for theconnection of a gas supply thereto in communication with said stempassageway and having terminal means for the connection of power supplyleads thereto in circuit with said electrical conduits.

9. The apparatus defined in claim 8, wherein said stem includes a sheathof refractory type insulating material surrounding the gas passagewayand said conduits are embedded in the sheath.

References Cited in the file of this patent UNITED STATES PATENTS1,371,094 Holslag Mar. 8, 1921 1,847,864 Cross Mar. 1, 1932 1,898,926Aarts et al. Feb. 21, 1933 1,927,135 Sammons Sept. 19, 1933 2,398,427Hediger Apr. 16, 1946 2,441,319 Harding May 11, 1948! 2,471,695McCullough May 31, 1949'

